[improve] doc

Author: Ken Berkeley

README.md

@@ -10,5 +10,5 @@
 [Online examples](https://OneWayTech.github.io/vue2-datatable/examples/dist)
 
 [npm-url]: https://www.npmjs.com/package/vue2-datatable-component
-[npm-v-img]: http://img.shields.io/npm/v/vue2-datatable-component.svg
-[npm-dl-img]: http://img.shields.io/npm/dm/vue2-datatable-component.svg
+[npm-v-img]: https://img.shields.io/npm/v/vue2-datatable-component.svg
+[npm-dl-img]: https://img.shields.io/npm/dm/vue2-datatable-component.svg

doc/_coverpage.md

@@ -6,5 +6,5 @@
 [The best Datatable for Vue.js 2.x which never sucks ↓](README)
 
 [npm-url]: https://www.npmjs.com/package/vue2-datatable-component
-[npm-v-img]: http://img.shields.io/npm/v/vue2-datatable-component.svg
-[npm-dl-img]: http://img.shields.io/npm/dm/vue2-datatable-component.svg
+[npm-v-img]: https://img.shields.io/npm/v/vue2-datatable-component.svg
+[npm-dl-img]: https://img.shields.io/npm/dm/vue2-datatable-component.svg

doc/en/i18n.md

@@ -42,7 +42,7 @@ Wow, it's just a normal object!
 Copy and paste from [`src/index.js`](https://github.com/OneWayTech/vue2-datatable/blob/master/src/index.js):
 
 ```js
-module.exports = {
+var Datatable = {
   install: function (Vue, options) {
     var locale = options && options.locale || {};
 
@@ -54,6 +54,12 @@ module.exports = {
     Vue.component('Datatable', require('./Datatable.vue'));
   }
 };
+
+if (typeof window !== 'undefined' && window.Vue) {
+  window.Vue.use(Datatable)
+}
+
+module.exports = Datatable;
 ```
 
 Apply to [`src/LimitSelect.vue`](https://github.com/OneWayTech/vue2-datatable/blob/master/src/LimitSelect.vue):

doc/zh-cn/i18n.md

@@ -42,7 +42,7 @@ module.exports = {
 本组件采用的是最简单的方案（见 [`src/index.js`](https://github.com/OneWayTech/vue2-datatable/blob/master/src/index.js)）：
 
 ```js
-module.exports = {
+var Datatable = {
   install: function (Vue, options) {
     var locale = options && options.locale || {};
 
@@ -51,9 +51,15 @@ module.exports = {
       return locale[srcTxt] || srcTxt;
     };
 
-    Vue.component('Datatable', require('./src/Datatable.vue'));
+    Vue.component('Datatable', require('./Datatable.vue'));
   }
 };
+
+if (typeof window !== 'undefined' && window.Vue) {
+  window.Vue.use(Datatable)
+}
+
+module.exports = Datatable;
 ```
 
 模板中是这样操作（以 [`src/LimitSelect.vue`](https://github.com/OneWayTech/vue2-datatable/blob/master/src/LimitSelect.vue) 为例）：